The life of a block of non-volatile storage, such as a block of flash storage, may depend on the number of times the block is erased or rewritten. For example, NOR-based flash may last for 10,000 to 1,000,000 erase cycles. NAND flash may have ten times the endurance. The repeated erasures may wear out a chemical component of flash and other types of non-volatile storage. Layers of the chemicals may lie between pairs of transistors. Writing to a location may require setting a charge in the chemicals between a transistor pair, and erasing the value in a location may require application of an electric charge to the chemicals. Repeated application of the charges may destroy their potency. In many types of non-volatile storage, such as flash memory and EEPROM, writing and erasing is done a block at a time. Thus, a series of erasures and writes to separate locations of a block may cause multiple erasures and writes to the block as a whole. Further, the failure of a single block may cause the failure of the entire system of non-volatile storage. Thus, the life of an entire chip of non-volatile storage may depend on the life of its most used block.
In some current systems, some blocks of non-volatile storage are used intensively. For example, typically firmware components and non-volatile system storage area are fixed in flash device. System firmware typically uses a fixed range of flash space to serve as non-volatile storage. New introduced technologies such as IPMI (Intelligent Platform Management Interface) and WHEA (Windows Hardware Error Architecture) need non-volatile storage to save event or error logs to provide full functionality. Advanced system software such as server management and error logging may impose much more frequent erase and programming operations on non-volatile storage area. This more frequent use may introduce potential risks of device damage to the non-volatile storage and system instability. Because the frequently used space may be a narrow portion of the chip, these portions may be near failure while other portions are rarely used.